A diesel engine is generally a long lived internal combustion engine because of the efficiencies inherent in such an engine. One of the problems, however, with the diesel engine is that the upper compression ring i.e. at the upper portion of the piston, is subject to failure because it is not properly cooled, thus causing distortion and uneven wear.
Another problem with the diesel engine is caused by the high compression of air in the cylinder (over 500 lbs. at 600 r.p.m.) to which fuel is injected. Ignition of the fuel and air mixture takes place producing power to move the piston down, at the end of the stroke, port and exhaust valves are open at the same time allowing exhaust of spent gases and scavenging of material within the cylinder. The exhaust valves then close and compression is begun repeating the cycle. Due to the short time between cycles, the piston has very little time to cool which can cause the top ring to start collapsing at the ends often causing total failure of the whole ring which is usually stuck in the ring groove. This failure of the ring causes hot gasses to reach other rings below the fire ring, lower the compression and cause the engine to smoke. With proper cooling by oil on the underside of the piston head most occurrences of this will be eliminated. Because of the continuous pressure, the bushing around the wrist pin, which holds the piston to the connecting rod, may be worn quite badly and still not generate noise. The absence of a tell tale noise is a result of the fact that the piston is continuously forced downwardly against the upper portion of the wrist pin regardless of the amount of wear. It will be immediately apparent that if there is no obvious indiciation of wear upon the bushings or on the wrist pin the first notice that the operator will have of a worn wrist pin or bushing is when there is the ultimate failure which could permanently damage the engine.
Various attempts have been made to alleviate the problems hereinabove noted and one of particular note is the U.S. Pat. No. 2,092,599 granted to W. E. Brill on Sept. 7, 1937. Whereas Brill teaches the broad concept of retaining the lubricating fluid in the upper portion of the piston to provide cooling and lubrication thereby his apparatus requires a major modification to the piston itself. The bores 20 must be placed within the skirt and the shroud or baffle 13 must be secured to the interior of the piston by means of bolts or the like. Further, the retention of fluid above the baffle 13 does not assist in the lubrication of the wrist pin as will be obvious when viewing FIGS. 1 or 3.
With the above noted problems and the known prior art attempt in mind it is an object of the present invention to provide an easily installed seal for use in the interior of a piston for an internal combustion engine. The seal is designed to retain lubricating oil above said seal and thus assure proper cooling of the upper portion of the piston.
Another object of the present invention is to provide a seal for use in the interior of a piston which causes a buildup of pressure in the upper portion of the piston thus forcing lubricant to the bushings surrounding the wrist pin and provide proper lubrication thereto.
It is yet another object of the present invention to provide a seal for use in the interior portion of a piston for an internal combustion engine wherein said seal is a kit which may be applied to the interior of the piston during an overhaul of the engine. Said kit requiring no alteration to the interior of the piston to assure proper retention and placement.